High-speed motor boat



April 14, 1953 H. A. BECKER 2,634,698

HIGH-SPEED MOTOR BOAT Filed Feb. 26, 1948 [/2 2/6/7 1' Afar/ Ado/2 56442? Patented Apr. 14, 1953 UNITED STATES PATENT OFFICE HIGH-SPEED MOTOR BOAT Harry Adolf Becker, Stockholm, Sweden, assignor to Aktiebolaget Beckerbat, Stockholm, Sweden, a. corporation of Sweden Application February 26, 1948, Serial No. 10,958 In Sweden April 21, 1941 Section 1, Public Law 690, August 8, 1946 Patent expires April 21, 1961 3 Claims. (Cl. 114-665) The present invention refers to an arrangement in high-speed motor boats, particularly in heavy boats or such that are intended for heavy loads, such as motor torpedo boats, with a generally V-shaped prow suitable for progress in high sea and provided with a step or steps athwart ships.

The invention is principally distinguished by horizontal or substantially horizontal additional carrying planes arranged athwart ships on both.

sides'of the prow portion, said carrying planes being located outside the normal cross sectional outline of the V-shaped prow portion and extending astern to about the half or somewhat more than the half, for instance to about 60% of the length of the boat, while being inclined astern,

so that their rear end is situated at or near,-

preferably somewhat below the real water line at'normal trimming, in combination with outwardly directed lengthwise steps extending in the'bottom surface abaft said additional carrying' planes, and these lengthwise steps being ar ranged in the break line between a middle bottom surface and side bottom surfaces extending at an angle to the horizontal plane, obliquely outwards and upwards, the width of said middle bottom surface, counted from the longitudinal mid'ship line, being at the forward portion (adjacent to the step athwart ships) to .the width of the side bottom surface as 1.5 :.1 to 3:1.

The invention will. be described. more closely.

hereinafter withreference to an example of embodiment of a motor-torpedoboat illustratedin' the-accompanying drawing, Fig. 1 is a side view of th'e boat- Fig. 2 is'a-plan view of the boat on one side of the longitudinal midship line, and-Fig. 3'shows the body-plan of the boat. Fig. 4 shows the body-plane of the boat with the additional planes built into the hull.

In the drawing, i designates the additional plane pertaining to the one side of the boat, said plane being supposed, in the examplev illustrated in Fig. 3, to have been applied afterwards onto a boat the construction of which is already finished, although it may obviously be secured or' built into the hull already from the begin ning as shown in the body-plane in Fig. 4. The lower'active surface of the additional plane facing the water is denoted by 2. Said surface being arranged in the place where the bilge is normally situated. On the upper side, the additional plane merges in a wedge-like manner into the normal planking.

The additional plane, which extends for a distance of between and of the length of the boat in the water line, commences, in the example shown, immediately at the prow and continues to a step 3 athwart ships, which step is located approximately at the middle of the boat. In this zone, the boat is substantially V' shaped, as will be found from the body-plan, so

that the prow shows a configuration suited for progress in heavy sea. Astern of the step, the

bottom of the boat is of a more plane shape, but 1 is even here formed in a special suitable manner face 2 with the stern'endthereof, to 15 at the most, but is not .very wellbelow 3. The most suitable inclination may be stated to be about 5 to 7 in the construction shown.

The additional plane is preferably of about the same width all over the length thereof, save, perhaps, for the fore portion thereof, which may be drawn in to some extent; The'average width of the additional plane preferably amounts -to between and /40 of'the greatest-width of the boat, preferably'to about 5 thereof. Viewed from the side of the boat, the additional planeis preferably bulged downwardly, and the largest bulge may'a'mount to about 30% to prefer-- ably to about 75% of the width of the additional plane.

plane is preferably at right angles or"approxi 4 i mately at right angles to the planking above the surface 2. In the example shown, the active surface 2 of the additional plane follows the bilge of the prow, which in the V -ribbed boat is located in the break line between the'bottom plane 4 and the side plane 5 of the planking. Expressed another way, the active surface 2 may form at the fore-end an angle of, for instance, 110 to 115 to the vertical line, while at the rear edge thesame angle may be about to The after-part of the boat is provided with lengthwise steps 6, the heightof which may amount,- for instance, to between 0.5% and 2%" of the greatest width of the boat. The height".

of said lengthwise steps does therefor, at least at the bottom surface adjacent the athwart step,-

The active surface? of the additional not exceed 2% of the greatest width of the boat. In the example shown, the bottom of the boat in the after-part shows, viewed on both sides of the longitudinal .midship line, a .middle bottom surface 7 and a side bottom surface 8 which surfaces, viewed on the whole, form an angle with one another the step being arranged in the break line between said surfaces. In the forepart, that is to say adjacent to the step athwart ships,

the width of the middle bottom surface, counted from the longitudinal midship line, is preferably related to the width of the side bottom surface according to the ratio :1 to 3:1, while the same ratio abaft, that is to say at the stern,'maylbe 0.75:1 to 2:1, preferably about 1:1. As will be seenfrom the body-plan, in the illustratedexample the middle bottom surface and the side bottom surface have approximately the same inclination on each side of the longitudinal midship line adjacent to the step athwart ships. This inclination may be between 5 and for example, preferably about 15? to the horizontal plane. 1 Toward the stem, the surfaces continuonslyassume anever increasing brea-k relatively to each other. It is preferred to have the middle bottom surface aftermost extend substantially horizontally, while theside bottom surface aftermost forms an angle to the horizontal plane whichamounts to about.30. The last-mentioned angle may betaken to vary between 20 and 40, for example.

In experimental investigations, the illustrated shape of the bottom of. the after-part has been found tohave an exceedingly good stabilizing effeet .in cooperationiwith the additional planes whilehavingatethe same time a favourable eiiect onthe manoeuvring capacity of the. boat.

,Asregards the shape of .the-iorepart, such as it'has been indicated 'in the .example. shown, it might be stated in addition that the angle shown in the bodyplan may be. advantageously between 5 and.20, for instance between 15 and 17, the corresponding angle for the remaining :ribs then varying-in a corresponding degree.

Inthe. example shown, theadditional plane l is shown as being .made inonecoherent length. It is conceivablephowver, 'to. divideitup lengthwise into .two or more parts,;which may have somewhat difiierentrinclinationsi'to the horizontal plane. and to the water respectively. I

In .the example shown, thebottom .of' the boat is, as. willbe clearly seen-from the body-plamqof exactly or nearly exactly thesame "width from the .step; athwart ships and up to the-stern. It isobvious, however, that the shape of the bottomaof the. boat. may vary in this respect, but the. shape as illustrated hasbeen .found to be veryadvantageous from the. point of view of carrying-power.

In the. drawing, nates the straight .the chain-dotted line a desigbasic construction line .of the bottom. This line forms a tangent to the mal bottom line of'the boat. at'three points, one D at the prow, another 0 at the step athwart'ships, and a .third at at the stern. Between these points the bottom of. the. boat is drawn in; This three point hanging hasbeenrfound to be of great importance.

What I claim: is:

.1. .Ahull for high-sspeedzmotor boats, particularly ,heay-y'boats and. suchthat are intended for heavy loads, such torpedo motor boats, .comprising a step athwart ship, :said hull having a generally :V-shaped prow portion suitable for progress"-in'.-high.sea,ssubstantiallyhorizontal carrying planes arranged athwart ship on both sides of the prow portion, said carrying planes being located outside the normal cross sectional outline of the V-shaped prow portion and extending astern from the stern of thehull toabou't 50 per cent to 60 per cent of the length of the hull and terminating in said step while being inclined from the stern downwardly astern, so that their after end isv situated in the vicinity of the real water line at normal trimming, in combination with outwardly directed lengthwise steps extending in the bottom surface abaft said carrying planes. said lengthwise steps originating in said step athwart ship and extending along all of the afterpart, and being arranged at the line of intersection between a middle bottom surface and side bottom surfaces extending at an angle to the horizontal plane, obliquely outwards and upwards, said middle bottom surface and the said side bottom surface having approximately the same inclination on each side of the longitudinal; midship line 'at'the forepart oi the-surfaces adjacent to the step athwart :ship, said inclination being between? and 20 to the horizontal plane, while said surfaces assume. astern an ever increasing. break relatively to each other,'the middle bottom surface being aftermost substantially horizontal, while the side bottom surface in the same aftermost place forms an angle'to'the horizontal plane between 20 and 40.

2. A hull for high-speed motor boats, particularly heavy boats and such thatare intendedifor heavy loads, such astorpedo motorv boats, cmprising. a step at thekeel .line, said hull having a generally V-shaped prow "portion suitable 'for progress in high 'sea, said prowin front of said. step at the keelllneishowing aninward ben'd,.'sub stantially horizontal carrying planes arranged athwart ship on both ."sides .of theiprow'portion, said carrying planes being. located outside. the normal cross sectional outline of thew-shaped prow portion and extending asternirom the stern of the hull to about .50 percent to 611 percent of the length of the .hullxwhile being inclined, from the stern downwardly astern, so that their after endyis situated inthe. vicinity of the real water line at normal trimmingpin :combinationwith outwardly directed lengthwise .steps extending. in,

the. bottom surface .abaftrs'aid carrying :planes,

and being :arranged. at .theline of intersection. be-- tween :a middle bottomsurface and side bottom surfaces extending at'an angle .to the horizontal plane, obliquely outwards-.andnpwards, said 1hi'd-; dle; bottom. surface andthe :saidsi'de bottom sure; face. having approximately the :same. inclination;

onieach-sideof the longitudinal midship line at.

the forepart of the. surfaces: adjacentytothestep: .said inclination. being between 5- athwart ship, and 20 to theliorizontal'plane, 'whilesaid-isur facesassume astern anzever increasingbreak'relatively to each other, the. middle bottom surface being aftermost substantially horizontal, while the side place forms an angle to the horizontal plane between 20 to 40, the bottom of the after part abaft the said 'step showing a constructional depth increasing. toward. the stern, the outline of thebottom of thehull being such in side elevation that the aftermost portion, the lower edge of the step, and a point in the forepart of the hull are: on the. same straight line.

3. A hullfor high speed. motor boats, particu+ larly heavy boats and such that are intended for heavy loads, such astorpedo .motor boats, =.com prising 'a. generally: v-shaped prow portion suit bottom surface in the same aftermostable for progress in high sea, substantially horizontal carrying planes arranged athwart ships on both sides of the prow portion, said carrying planes being located outside the normal cross sectional outline of the V-shaped prow portion and extending astern from the stern of the hull to about 50 per cent to 60 per cent of the length of the hull while being inclined from the stern downwardly astern, so that their after end is situated in the vicinity of the real water line at normal trimming, in combination with outwardly directed lengthwise steps extending in the bottom surface abaft said carrying planes, said lengthwise steps being arranged at the line of intersection between a middle bottom surface and side bottom surfaces extending at an angle to the horizontal plane, obliquely outwards and upwards, the width of said middle bottom surface counted from the longitudinal midship line aftermost (adjacent to the stern) is related to the width of said side bottom according to the ratio, 0.75:1 to 2:1, and the width of said middle bottom surface, counted from the longtudinal midship line, being at the forward portion to the width of the said bottom surface as 1.5:1 to 3:1,

said middle bottom surface and the said side bottom surface having approximately the same inclination on each side of the longitudinal midship line at the forepart of the surfaces, said inclination being between 5 to 20 to the horizontal plane, while said surfaces assume astern an ever increasing break relatively to each other, the middle bottom surface being aftermost substantially horizontal, while the side bottom surface in the same aftermost place forms an angle to the horizontal plane between 20 and HARRY ADOLF BECKER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,746,912 Smith Feb. 11, 1930 1,935,622 Eddy Nov. 21, 1933 2,251,621 Van Hoorn Aug. 5, 1941 FOREIGN PATENTS Number Country Date 9,896 Great Britain of 1892 319,982 Great Britain Oct. 3, 1929 

